Building the Future: Significant Progress on 2018 Initiatives Will Help Shape Codes and Standards in the Future

2018 State of the Industry Report

By
Daniel J. Walker, PE,
General Manager, Metal Building Manufacturers Association,
and
W. Lee Shoemaker, Ph.D., PEDirector of Research and Engineering, Metal Building Manufacturers AssociationPosted February 01, 2018

Daniel J. Walker, PE

With the adoption of the 2018 International Building Code (IBC), the Metal Building Manufacturers Association (MBMA) will now move forward with continued research initiatives that will help shape codes and standards through the next decade and beyond. Here are some of the influential research activities that will spur future change.

W. Lee Shoemaker, Ph.D., PE

Seismic Behavior

Our goal with seismic research is to expand the limits where metal building frames are considered appropriate in higher seismic regions and to drive the methodology for designing metal building frames into the next generation. MBMA made great strides in 2017 to determine the appropriate seismic design parameters that should be used for our frame types. Dr. Vahid Meimand, NBM Technologies, Blacksburg, Va., has made enormous progress in the development of tools and analytical processes required by FEMA P695, which is the process used to qualify such designs for code approval.

The MBMA Seismic Steering Committee has established the first three prototypes for metal buildings intended for processing through the analytical modeling methodology. Preliminary results are very promising and the MBMA Technical Committee is excited about the prospect of producing beneficial results from this massive research effort. We are hopeful the results of this work will be even better performing frame systems that are also competitive in the marketplace.

Wind Research—Structural

Recent changes in the ASCE 7 standard have significantly increased the design wind pressures for all types of low-rise buildings, including metal buildings. MBMA is working to conduct new research to determine more appropriate code required design wind pressures for metal building structures in several areas. First, a study by Gill Harris is evaluating the wind loads on continuous lapped purlin and girt systems. Currently, metal building designers calculate applied purlin wind loads based on an area-average of a fluctuating pressure profile along a purlin span. The new approach would spread the high-pressure peaks over a larger area of continuous framing systems, reducing the required design wind load.

In a related effort, Dr. Peter Vickery, Applied Research Associates, Albuquerque, N.M., is evaluating a refinement to a parameter (Wind Directionality Factor) used to calculate ASCE 7 design wind pressures. This parameter accounts for the probability that wind generated in a design-level storm may not approach a building at the exact angle that would create the highest-pressure spike seen in wind tunnel testing. Preliminary studies indicate that this factor may be reduced, decreasing the required pressures imposed on all portions of buildings. MBMA’s intention would then be to introduce this topic at ASCE 7 Wind Subcommittee meetings for potential adoption into ASCE 7-22.

Wind Research—Roofing

Wind tunnel research on standing seam roof behavior was recently completed at the Insurance Institute for Business & Home Safety (IBHS). Now, MBMA is assisting in two additional research activities underway through insurance-funded groups. The first project is at Western University in London, Ontario, Canada, under the direction of Dr. Greg Kopp. This project is a phase 2 extension of the IBHS wind tunnel research that was previously completed on a 30-foot by 45- foot by 10-foot gabled metal building at the IBHS research facility in Richburg, S.C. The new MBMA study seeks to replicate the loading from that study, but instead of wind, using a top-mounted air bag system capable of duplicating nearinstantaneous wind suction profile changes along a roof.

The intent is to drive the wind pressures to a higher level than could be obtained in the full-scale tests at IBHS and then examine the standing seam roof behavior at near-capacity levels. This will help us refine strength predictions. We are finding that metal roof systems actually have more capacity than current test methods predict. Our goal is to tap into some of that overcapacity in the hope of offsetting some of the increases in required design wind pressures to be introduced in building codes, based on the 2016 ASCE 7 standard.

MBMA and ICC Build Educational Alliance

The examples above are a sampling of the work we are doing to influence codes and standards. Many more research projects are underway, and we welcome participation in our research efforts from firms throughout the metal building industry. We are also pleased to report that, in 2018, we will now be co-branding our new manuals and technical guides with the International Code Council (ICC). The confidence that the ICC is placing in us affirms the quality of what we bring to the table. We are confident that having the MBMA and ICC logos on the cover of the metal building guides we produce will enhance the perception and position of metal buildings in the greater building construction marketplace.

Daniel J. Walker, PE, is associate general manager of the Metal Building Manufacturers Association (MBMA).

W. Lee Shoemaker, Ph.D., PE, is MBMA’s director of research and engineering. Details at www.mbma.com.